Ok i've heard and read about Racing Beats full turbo exhaust system. Some how they have the ***** to claim 57 hp at the rear wheels just from bolting on there exhaust. Now i'm callin Bull Sh*t. I refuse to belive just exhaust and a down pipe could give you that much. I will stand by this untill someone shows me some dyno results on a t2. Now dont get me wrong i want someone to prove me wrong and make me look the fool because if you do i know exactly what exhaust i'm running to the store to buy.

 

Well, I don't believe it will make quite that much, but I have ridden in some NAs that have a full RB exhaust and they are noticably quicker than my stock exhaust is.

Gotta remember, those damn cats are killing your engine. They are like a friggin noose around the motor's throat. Plus, you get much higher flowing mufflers.

I, too, would like to see some dyno results and see if they are close to that much power increase.

I believe they claim as much as 57 hp increase, but that won't happen on a perfectly running turbo. I think that much power will happen on a turbo w/ partially clogged cats and/or mufflers that is facing restriction. Then, on top of a better designed system, you remove the restriction and gain power from both aspects.

 

No...it really makes that big of a difference. My friend had a T2 that made 220 to the wheels after the RB turboback alone. You compute how much that is to the flywheel, and Ill bet you come close to 57 above stock.



What you NA guys fail to understand is that by adding a free flowing exhaust ( such as the RB system ) not only do you get the normal power gains you would on an NA...but you also get a big jump in boost. Thats why they sell an FCD with their systems.

 

The graph is in their Catalog and its also been posted on this site within the last two months.

 

i don't have any cats i didn't really notice that big of a power gain. I also have wider mufflers and bigger pipes.

 

Remember, with the full exhaust and no back pressure the boost will rise to @ 10 lbs. If stock is, let's say 6, we have a 4 lb increase in boost=@ 27%.
200 + 54 (27%)=254 HP
Rule of thumb, for every increase of 14.7 lbs- HP will double-all else being equal.

 

Thats not a rule of thumb. Thats called a "theory" of what would happen in "ideal conditions"

Youll never see that in real life so please stop spreading this crap.

 

Do you have a TII?

 

What CRAP are you talking about, my '89TII went to just over 10 lbs with the RB exhaust. 8lbs with the Bonez DP and Hi flo cat.That's THEORY!
As for the "rule of thumb" you're correct, it's a rule of thumb, but that's what were talking here.If you upgrade and increase boost accordingly, you'll double the HP every 14.7 lbs. How do you think competition cars get so much HP-40/50lbs boost-THEORY.

 

Look for some dyno & 1/4 mile info and you'll see there's a whooping big difference with a full exhaust. Keep in mind there are no cats in that system.

Doesn't the RB Full exhaust give a larger gain on the S4s than the S5s, due to the wastegate?

 

You really need to learn to read.

In case you didnt notice, I was the first in this thread to say it would yield you ~57 hp.....asshat

Secondly, I was calling your "rule of thumb" crap because its not a rule. Its a "theory" ( do you know what that means? ) of what will happen in "ideal conditions" ( do you know what those are and that they only exist on paper? )

Grow up and pass 2nd grade english before you start attacking people








EDIT: Heres something that ought to keep you busy for a while.

If X increase in boost yields Y amount of hp ( which is your "rule of thumb" ), How is it that a stock FC turbo @ 14.7 PSI makes less power than a T04 @ 14.7 PSI?



Your logic is so flawed its almost sickening. Just because you read something on the internet, doesnt mean its true

 

its not so much the exhaust but the fact that it creates almost 2X the boost the stock turbo does and thats where your HP gain is made.

 

This was my car after installing the full racingbeat exhaust, severely ported wastegate, upgraded fuel pump, and an Apexi SAFC (Dyno tuned). The mods besides the exhaust were for safety not added performance.

203.4 rwhp is about 235-240 flywheel hp. 240-183=57. Its acurate.

 

S4 or S5?

 

S4, sorry

 

Do you have a stock dyno run? I was wondering what the completely stock run would look like.

Thats where everybody gets confused. They are confused with the Mazda paper HP vs. the actual wheel run measured on the dyno. The RB catalog that I have says 59hp gain on a 1987 T2.
My catalog doesn't have any dyno runs in it. And, it makes no claim for the s5 HP increase.

Another area of confusion tends to be where the HP is made. Just because they said 59hp increase, doesn't mean it is a 59hp increase in peak hp. It could be a little higher or lower in the power band in a point to point comparison.

For example:
And this is a lame comparison: If a stock engine made 140 wheel hp at 6000, but, due to power drop off, made only 110 at 7500rpm. If you eliminate all exhaust restriction, add boost/fuel, and then squeak 170hp at 7500 doesn't mean you're gonna make the same 60hp increase at 6500 rpm or any other rpm. Hell, you might only get 30-40 at the previous HP peak rpm. But, the area under the curve has changed greatly. That is the most important thing.

Nobody here wants to admit that the 180-200hp T2 only has 140hp or that the NA only has 100hp. Thats why some of the power gains sound unbelievable.

I remember an FD pull. It made 210hp. Mazda said it made 255hp. Saabguy might be making a little more than his 240hp flywheel guestimate.

And here is the another thing to think about--torque.
A 20ftlb increase in torque at 4000 rpm gives 15hp.
A 20ftlb increase in torque at 8000 rpm gives 30hp.
This is why the rotary responds well with upper rpm tuning. A mild increase in torque at 7000rpm or more, gives a good HP increase. This makes the NA true dual's power increase believable.

 

I don't think is says a max gain of 57 either.... so maybe it gains it at 4000rpm or so. like from 100hp to 157 hp at 4000. but it makes a big difference across the whole band.

 

I posted my S4 dyno run awhile back using the RB full system...I listed the mods too

 

I will post it tomorrow.....when I get to work.

 

umm i wasnt going to really say anything but why are you soo angry? just because he isnt right? that is no reason to resort to childish insults like "grow up and pass 2nd grade" seriously what is that? he just simply added his opinion of what he thought was right and just because it isnt the same thing you think is right you jump down his throat. he might need to pass 2nd grade or whatever but it is MY OPINION it might defer from yours that you are acting like a 2nd grader
:rolls eyes: the point of this was not to talk noise or anything just to say chill out man! you could have worded things alot nicer that waht you did. ok i said what i had to say and im outta here. sorry for getting off the topic.

 

Well right now I'm in the process of gutting my cats on my 87' T2. Am I going to see a noticable gain in HP from that?

 

look fool!!!

"Performance tests on a Dyno Jet chassis dyno have shown a 5-7 HP gain over the stock system." (http://www.racingbeat.com/FRmazda2.htm)

Where are you geting 57 HP?

Read it!

 

Thats the catback. The 59hp is the complete exhaust system. So stop the name calling.

Here, let me quote that website:"The bolt-on exhaust system increases horsepower approximately 32% - a 59 HP increase on a 1987 Turbo II RX-7!"

 

No Fool!

Im seeing the 57 hp here

"This complete exhaust system is 3" out of the turbo, 3" Pre-silencer, then splits into two 2 1/4" pipes into the two mufflers. Construction is heavy wall mild steel, with stainless packing in pre-silencer. Tips are polished stainless.
HP increase is approximately 32% (a 59HP increase) on a 1987 Turbo II .Boost increase is 4-6 psi. Fuel cut controller is required to prevent fuel shut-off to rear rotor due to the increase in boost pressure seen by the factory computer."


http://www.mazdatrix.com/r-extii.htm

 

Aww, you got it before i did